(Edit: removed unnecessary sarcasm) I'm rather baffled that it's possible to not know that sugar is bad for your teeth, as it's pretty much the most often repe

(Edit: removed unnecessary sarcasm) I'm rather baffled that it's possible to not know that sugar is bad for your teeth, as it's pretty much the most often repeated fact about teeth ever. Technically sugar itself doesn't do anything to teeth. But sugar is food for bacteria. Sugar in mouth = mouth bacteria happily multiply and literally form a biofilm covering your teeth (plaque). Some of them excrete acidic metabolic products. Acid dissolves enamel (hydroxyapatite). The bacteria infestation also irritates gums and causes gingvitis and so on. Less food for bacteria = fewer bacteria = healthier teeth.